A mixer vehicle provided with a mixer drum capable of loading so-called uncured concrete such as mortar, ready-mixed concrete and the like has been used.
JP2007-278430A discloses a mixer-drum driving device of a mixer vehicle provided with a hydraulic pump driven by an engine of the vehicle and a hydraulic motor for rotating the mixer drum by being operated by an operating oil discharged from the hydraulic pump. In this mixer vehicle, an electric motor capable of rotating the mixer drum when the engine of the vehicle is stopped is provided.